WALTHAM — The dunk happened sometime today between 1 and 2:30 p.m. when the Celtics had their practice closed off to the media, but it did happen.

Doc Rivers worked the Celtics hard Monday, one day after a preseason game with the Nets, and one day before a back-to-back set with New Jersey and then Toronto in Hartford. During the session, Kevin Garnett went up for a lob and brought it home.

“Kevin was great,” Rivers said. “I don’t think he came out today. He’s getting stronger and stronger. The only thing left, today, he caught a lob and dunked it. It was an amazing dunk and everyone was like, ‘Whoa, we haven’t seen that.’ He’s not as explosive yet, but it will come. You can see it. When he did it he yelled out, ‘Oh I can do it.’ That was good to see.”

KG’s reaction?

“I think Doc wants me to grow wings and fly,” Garnett said. “I tell him just to be patient. The wings are coming.”

The wings, and everything else, are coming into focus for the Celtics as they reach roughly the midway point of training camp. The starting five is back and healthy and the reserves have shown enough in the preseason games that the bench seems far more settled than it has in the past.

Still, there remains work to be done incorporating the new players ‘ Rasheed Wallace and Marquis Daniels particularly ‘ into the offensive and defensive systems as well as learning the little things about each other that only come with time and reps.

“Even though everyone has a high IQ when it comes to basketball, we still have chemistry [things to work on],” Garnett said. “Where ‘Sheed likes to have the ball, where Marquis likes isolation and everybody understanding everybody’s game. It’s not a big thing, but it’s something that you have to give a certain amount of attention to. The new guys have to learn our schemes and understand terminology.”

There’s no question the Celtics are feeling good about where they are with the season-opener at Cleveland looming in a little more than two weeks. A big part of that is fact that the players came into camp in basketball shape.

“Every guy on our team has come to camp in better shape than they were last year,” Rivers said. “Eddie [House] came to camp in phenomenal shape. Kevin, conditioning-wise, is probably not where he was last year because he spent half the summer not being able to work out. But everyone else: Paul [Pierce] is in great shape, [Glen Davis] is in great shape. A lot of that is that we lost and no one likes that feeling. You want to do something about it.”

NOTES: Part of the reason that Rivers worked the team so extensively Monday is that he plans to rest the veterans in at least one of the next two games. Look for the coach to use that time to begin working on some rotation patterns. Rivers said that he is set on the first four off the bench ‘ House, Daniels, Wallace and Davis ‘ and then the rest will sort itself out depending on matchups.

Pierce turns 32 Tuesday (look for a story by colleague Jess Camerato that day) and while the captain was not in a mood to reminisce, Garnett offered his thoughts on his teammate. “Paul makes things easier,” Garnett said. “I’m not going to lie about that. He not only makes things easier, but simpler. Offensively, things get simplified, plus a lot of things he and I don’t need to talk. We have a bond and a chemistry that’s unspoken.”

Pierce on rookie Lester Hudson, who is three months older than six-year veteran Kendrick Perkins: “He’s a 25-year-old rookie. How many of those do you have? He plays mature. He came in and he understands the game a little better than your average 19- or 20-year-old rookie. That’s good.”

With seconds left in regulation between Wallace’s favorite team, the Kansas City Chiefs, and Perkins’ hometown club, the Chiefs scored a touchdown to force overtime. It was enough to send Perkins back into the trainer’s room while Wallace gloated in the last-second comeback.

On Sunday afternoon the Celtics locker room became an NFL fan zone following their game against the Nets (recap).

‘Everybody has their own teams and they’re rooting for their hometown,’ said Michael Sweetney while he watched the game from his locker. ‘Especially with ‘Sheed with Kansas City, Perk with Dallas, Paul [Pierce] likes the Patriots, and I’m from D.C. so I’ve got the [Washington] Redskins, we all just get around and talk trash. It brings us together. We have a good time.’

For the Celtics, following football is another experience to strengthen their team chemistry. Many of the players, including Glen Davis and Marquis Daniels, played in high school. Their passion for the sport now brings them together in the pros.

‘We’re all football fans,’ said Davis, a New Orleans Saints follower. ‘Football’s an American sport. Every guy likes football, we like to talk about football, and everybody talks about athletes.’

According to Daniels, this game is a common thread among many NBA players. The Orlando native, who is a fan of any Florida football team, recalls friendly rivalries among teammates when he played for the Mavericks and Pacers. In many cases a lost prediction would result in having to wear the opposition’s jersey.

Sweetney, however, has never played for a team where Sundays are so significant.

‘This is my first team being around something like this, just the camaraderie, everything,’ he said. ‘It’s just something special right now. Like I told you before ‘ and I’m not bad mouthing other teams ‘ the two teams I’ve been on [Bulls and Knicks], we’ve never done this. Guys enjoy each other, not just on the floor.’

In that moment, Wallace enjoyed himself as he continued his celebration. Even though his initial outburst was directed at Perkins, Sweetney was not exempt from the cheers. As Sweetney explained, Wallace is a ‘true diehard fan’ who would stick by the Chiefs even if they only won one game this season.

Ray Allen played 15 minutes in the first half and got up exactly one shot.

The Celtics first unit ran the same play, and only that play, during the entire first quarter when they were operating in the half court.

In other words, it’s dangerous to read too much into any preseason game, let alone one that featured 35 turnovers and 56 personal fouls, but for the purposes of discussion, there were several bright spots for the Celtics on Sunday. Of note:

Kevin Garnett’s comeback continues: Garnett logged 21 minutes and scored 12 points to go with six rebounds. He was also moving up and down the floor with a noticeably easier gait.

“Sprint,” Garnett said when asked what he was most encouraged by. “I thought today I got up and down. I tried to put pressure on their defense, get in the middle, call for the ball. As far as being aggressive this is probably the most aggressive I’ve been since I’ve come back and played. Reaction time was a lot better, a lot faster.”

Garnett was also back to old feisty self as he got mixed up with New Jersey’s Yi Jianlian during the first quarter.

“Wasn’t nothing,” Garnett said. “He don’t know me, I don’t know him.”

Good day for the captain: Garnett shot 6-of-8 from the floor but he wasn’t the Celtics’ most effective scorer. That was Paul Pierce, who scored an almost effortless 25 points on 8-for-12 shooting, operating mostly against New Jersey rookie Terrence Williams. But once again the most encouraging sign for the Celtics beyond their general health was the play of the second unit.

“To tell you the truth I thought our second unit was a lot more impressive than we were,” Pierce said. “They were the ones that pushed the lead out and they’re looking like they’re jelling well together. We are still coming along as a unit, but that’s the process of preseason.”

The rotation begins to take shape: Much has been made about the versatility of the C’s second unit thanks to veteran additions Rasheed Wallace and Marquis Daniels, but as good as they’ve been, the team will begin to integrate the starters with the reserves into forming a cohesive rotation.

From the beginning of the preseason Doc Rivers has brought Wallace in first off the bench to get him time with the starters, but beyond that look for a few more combinations to begin taking shape.

“The one group we haven’t had ‘ Rasheed, Kevin, Eddie [House], Paul and Ray ‘ that’s a group that you’d like to have on the floor,” Rivers said. “You have to be careful with the point guard. The three teams that we’ve played all pressure all the point. That’s dangerous for us.”

Rivers has a bunch of options at his disposal, and depending on matchups, foul trouble or injuries, he can mix and match as the season progresses. Finding ways to utilize House (who scored 13 points) always will be a top priority.

As the preseason games begin to pile up, Rivers said he’ll give veterans Pierce, Garnett, Wallace and Allen time to take some games off. The Celtics have two back-to-backs coming up, with the first set coming this week when they play at New York Tuesday and then the Raptors in Hartford Wednesday. They have another back-to-back set next week as well, which seems like a good time to work out some rotation kinks.

Health update: Everyone played, with the exception of Tony Allen, who is working his way back from an ankle injury. “There’s going to be good days and bad days [for Allen],” Rivers said before the game. “We’re not going to know until he gets on the floor.”

The last time Rafer Alston, Tony Battie, and Courtney Lee played against the Celtics, they sent the C’s packing for the summer. The trio were members of the Magic team that eliminated the Celtics in Game 7 of the Eastern Conference semifinals. This year they are in a different uniform and noticed the Cs have a different look as well.

Alston, Battie and Lee were traded from the Magic to the Nets over the summer as part of the Vince Carter deal. On Sunday they got their first take at the Celtics with their new team during preseason action at the TD Garden (recap here).

‘They got a brand new season,’ Battie said. ‘I mean, you look and [Kevin Garnett] is back and Rasheed [Wallace] is part of it. They got a great steal in getting Marquis Daniels, and you have those three additions coming back in the team. So, I think they’re the team to beat, definitely.’

Last season a hobbled Celtics squad was outscored, outrebounded and burned from the 3-point line by the Magic. Without Garnett on the court and veterans Ray Allen and Paul Pierce overworked, the Celtics bench could not save the season. Now the additions of Wallace and Daniels give the team much-needed depth.

‘They get their big guy back and then they add Rasheed Wallace in there now,’ Alston said. ‘I think when you’re trying to take away a lot of their main guys, they have a lot of guys that can step up and stretch the defense or post up on the low block. They have a different dynamic to their team, especially from a defensive aspect for other teams.’

Both Alston and Lee agree the series would have been completely different if the Celtics had so many weapons last season.

‘They would’ve been a better team,’ Lee said. ‘They definitely would’ve been harder for a matchup because you can play Marquis at the 1 and you sub in Rasheed, so they keep a shooting big in at all times, so they definitely would have been better.’

Said Alston: ‘I don’t think we would have been able to roam a lot off of a lot of their guys ‘ [Rajon] Rondo, [Kendrick] Perkins, Big Baby [Glen Davis]. Those guys who really bring more scoring to the offense, especially from the bench standpoint.’

The combination of a healthy Garnett and a revamped second unit has Alston noticing a difference in the 2009-10 Celtics. Although he isn’t as willing as Battie to name them the best in the Eastern Conference, he can’t deny the changes on the court.

‘Whenever they have all their guys, they have a swagger,’ he said. ‘When someone goes down they don’t have swagger no more. That’s just how they are.’

“He warmed me up pretty good, got to shoot a couple of jump shots, felt good on my landing,” Allen told WEEI.com after the game. “I just thought I’d give it a shot.”

Allen went scoreless (0-2 FG) in eight minutes of play, contributing an assist and a steal while committing two turnovers and two fouls. He wasn’t playing for the box score, though. This was a test of his recovery.

“I felt good. I did some good things, I did some bad things. But most importantly, I just want to see how my ankle’s going to act tomorrow,” he said. “I got a little hands on deflections, my man couldn’t get past me, [but I] turned it over, being too aggressive, and didn’t let the game come to me are the bad things. But for the most part I was out there, I got up and down the court. Now I’ve got to see how it’s going to feel tomorrow when I wake up.”

For now, his anke bothers him. He soaked his foot in ice and noticeably favored it as he walked in the locker room after the game. But Allen is taking it one day at a time.

“It’s pretty sore right now but I can’t be [psychic Miss] Cleo in this situation to tell you how I’m going to be tomorrow,” he said. “So we’ll see what’s good. “

Marquis Daniels is entering his seventh NBA season, and he can’t help but feel like it’s his first.

Daniels made his debut as a member of the Celtics at the TD Garden on Friday night against the Knicks (recap here) Even though Daniels had played in Boston several times, this game felt different.

‘I’m very excited. I told the guys the other day, I’m like, ‘I feel like a rookie,’ ‘ Daniels said before the game. ‘I’m very excited to be playing here. I’ve played in here on the other team and I knew there’d be a big difference. The fans play a big role and they’re great.’

‘Coming here is just a great moment,’ said Sweetney, who had not played in the NBA since the 2006-07 season. ‘Coming in the building was like, wow. But coming into this locker room and the history and just being on this team is just amazing.’

Newcomers such as Williams point to the Celtics’ deep tradition as something they have never experienced in the NBA. Williams has played for the Hawks, Timberwolves and Kings over the course of his career.

‘It’s a great feeling,’ he said. ‘I know it’s not the same gym as the Boston Garden, but there’s still a lot of history here and in the city wearing green. It’s still a great feeling to be part of history.’

With the titles and electricity of the TD Garden come high expectations for the upcoming season.

‘I’ve never been on a team at the beginning of the season and everybody says, ‘We’re going to make the playoffs,’ ‘ Sweetney said. ‘But this team has won championships, so it’s a different feeling surrounding it.’

This has Daniels looking forward to the feeling he has wearing a Celtics uniform.

‘[The difference with the Celtics is] just knowing that we have a chance to be real special and we have a chance to do great things,’ he said. ‘There are a lot of great, hard-working guys, great veterans, great franchise, coaches and everything. It’s going to be a great situation.’

“He’s healthy. He has zero knee pain, but he does have shin splints and aches and all that stuff,” Rivers said. “So, you’ve got to watch that, especially during preseason.”

Rivers noted that while he is cautiously limiting Garnett’s playing time, he hopes to keep him on the court for more consecutive minutes. Garnett played 13 minutes on Wednesday’s game against the Rockets. He scored six points and grabbed five rebounds.

“What I’m trying to [do is get] him back to his playing normal minutes in a game, and he hasn’t done that since he’s gone out. And that’s been a long time,” Rivers said. ” So, what we’re trying to do, and I thought actually he didn’t play enough minutes in some ways in the first game in a row, and so we’re going to try to correct that and then build from there.”